This 1997 Ford F150 came in with three complaints. The power windows do not work. The wipers do not work and the interior lights do not work. Figuring that they were all related I decided to test the easiest system to access, the power windows. I pulled the driver’s side power window switch assembly up and checked for power at the light blue/black wire with the key on. No power.
I then went to the interior fuse box and removed the battery saver relay. It is the small relay second from the top left corner.
I checked for ignition power on the lower right terminal, 12 volts, good.
I checked for ground at the upper right hand terminal by first placing one lead of my voltmeter to a positive battery source, 0 volts, bad. That in itself is enough to show that the GEM module is faulty but I also looked at GEM data with a scan tool and saw that internal system voltage was 22 volts. Hard to do with a 12 volt battery. Diagnosis of a faulty GEM module. To see how to replace the module please click here.
This is the reading with a new GEM module across terminals 85 and 86. Just like it should be 12 volts. Another important note is that I asked the customer about water leaks on this side of the truck and also closely inspected everything as I disassembled looking for signs of water intrusion. Water leaks are a big problem with these modules.
Again with the new GEM installed there is now power on the light blue/black wire.
In case you have not already figured it out if the windows had to be operated to raise a downed window you could do one of two things if there is no power at the light blue/black wire. One, you could apply 12 volts to this wire with a jumper wire. Two, you could jumper terminals 87 and 30 together at the battery saver relay. The second will also test the wiring in the door jamb as well.
well,like i say. im gonna give it a shot regardless and see what happens. it’s a better starting point than where i was. i’ll report back and thanks again!
The difference is a prolonged soaking versus wet and dry within a few minutes to an hour. Not a guarantee that it is the problem but I have seen multiple problems with them on various Ford vehicles. The Crown Vic, Grand Marquis and Town Car are the most common with this problem.
keypad huh. ok i will check that out. if i am experiencing the problem and i do as you recomend should i notice the issue stop once the keypad is disconnected?? out of curiosity, if the keypad is causing this wouldnt i have this issue after washing the truck??? either way i am gonna check it out. im just curious as to why it only does it when the weather is badas opposed to anytime it sees water. like i said i will definately check it. thank you
Your symptoms, combined with the keyless entry pad, point to water intrusion into the key pad and false signals being created by corrosion in the key pad. Two ways to prove it out without diagnostic equipment. Remove the door panel and disconnect the harness connector to the key pad (make sure you seal up the two connectors with tape). When the weather is good and the problem has gone away, use tape and/or plastic to seal the keypad from the elements. Either way, if the problem does not return, the keypad is the cause of your problem.
yes it does. i dont have any issues with the keypads operation though…